How do I delete notes from track that were added via step entry?

Ardour 9. Just discovered the Step Entry.

According to The Ardour Manual - Step Entry

Step editing and recording MIDI via the track’s MIDI port cannot happen simultaneously.

What does “cannot happen simultaneously” really mean?

Because it seems I can record notes from an attached midi keyboard while in step editor.

The only issue: those notes are added read-only/greyed out in the track and I cannot remove them? Or can I somehow?

And is this intended behavior or a bug?

best,
Jens

The greyed-out part could be that your MIDI recording is on a lower layer. Right-click on the track header and try the stacked-layer-view (SHIFT+] IIRC).